halcyon

UK: /ˈhælsiən/ US: /ˈhælsiən/ ,(hal′sē ən)

WordReference Random House Learner's Dictionary of American English © 2025

hal•cy•on /ˈhælsiən/   adj. [often: before a noun]

1. calm;
   tranquil:
   halcyon weather.
2. happy;
   joyful;
   carefree:
   the halcyon days of youth.

WordReference Random House Unabridged Dictionary of American English © 2025

hal•cy•on  (hal′sē ən), adj. Also, hal•cy•o•ni•an (hal′sē ō′nē ən), hal•cy•on•ic 

(hal′sē on′ik). 
1. calm;
   peaceful;
   tranquil:
   halcyon weather.
2. rich;
   wealthy;
   prosperous:
   halcyon times of peace.
3. happy;
   joyful;
   carefree:
   halcyon days of youth.
4. of or pertaining to the halcyon or kingfisher.

n. 

5. a mythical bird, usually identified with the kingfisher, said to breed about the time of the winter solstice in a nest floating on the sea, and to have the power of charming winds and waves into calmness.
6. Birds any of various kingfishers, esp. of the genus Halcyon.
7. (cap.) [Class. Myth.] Alcyone (def. 2).

• Greek
• Latin alcyōn
• Greek halkyó̄n, pseudo-etymological variant of alkyó̄n kingfisher; replacing Middle English alceon, alicion
• Latin
• 1350–1400

Synonyms

• 1. serene, placid, pacific, untroubled.

Collins Concise English Dictionary © HarperCollins Publishers::

halcyon / ˈhælsɪən/ adjective
also: halcyonian / ˌhælsɪˈəʊnɪən/, halcyonic / ˌhælsɪˈɒnɪk/

1. peaceful, gentle, and calm

noun

1. a fabulous bird associated with the winter solstice
2. a poetic name for the kingfisher
3. halcyon days ⇒ a fortnight of calm weather during the winter solstice
4. a period of peace and happiness

Etymology: 14th Century: from Latin alcyon, from Greek alkuōn kingfisher, of uncertain origin